The present invention relates to propulsor systems, and more particularly to a pitchlocking system which utilizes a common ballscrew for operation with a ballscrew ballnut and a pitchlock screw nut thereby requiring fewer parts and less axial space.
In typical variable pitch propulsor systems, a plurality of propulsor blades, each pivotably mounted for movement about its longitudinal axis relative to a rotary hub driven by an aircraft engine, are operatively connected to a mechanical or hydromechanical blade pitch change system disposed within the hub assembly. Pitch change systems typically include a pitchlock for maintaining blade pitch in the event of a malfunction such as a loss in the system's hydraulic supply.
Conventional pitch lock systems often incorporate a pitch lock screw to provide a locking mechanism which prevents the blades from moving to a lower blade angle in addition to a separate ballscrew mechanism which is backdriven to rotationally drive the pitchlock screw. Although effective, such conventional arrangements are relatively complicated and require a relatively significant axial envelope within the hub assembly to mount both the ballscrew and pitchlock screw.
Accordingly, it is desirable to provide a variable pitch propulsor system with an uncomplicated and lightweight pitchlocking system having a minimal axial envelope.